Grinding mount holder assembly, apparatus and method for manufacturing a sample

ABSTRACT

Provided are a grinding mount holder assembly and an apparatus and method for manufacturing a sample using the grinding mount holder assembly. In an embodiment, the grinding mount holder assembly includes a mount in which a sample is fitted, a holder in which the mount is inserted, and a base on which the holder is installed so that it is capable of rotating. The base has a pressing member for pressing down the mount inserted in the holder. First one surface of the sample is exposed to one or more grinding wheels for grinding and polishing. Then the sample is flipped to expose the other side to the grinding wheels by rotating the holder 180 degrees within the base, and pressing the now-flipped sample downward through the holder until it is forced against the grinding wheel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional patent application claims priority under 35U.S.C. §119 of Korean Patent Application No. 10-2006-12187, filed onFeb. 8, 2006, the entire contents of which are hereby incorporated byreference.

BACKGROUND

The embodiments disclosed herein relate to a grinding mount holderassembly, and more particularly, to a grinding mount holder assemblyused for manufacturing a semiconductor sample, and an apparatus andmethod for manufacturing a semiconductor sample using the grinding mountholder assembly.

Because the size of the semiconductor device has been greatly reduced, atransmission electronic microscope (TEM) is often widely used to analyzesemiconductor device defects. To analyze the semiconductor using theTEM, a semiconductor sample for a TEM analysis must be prepared. Thesample manufacturing process must be precise to process a targetanalyzing point of a semiconductor wafer that is very thin (e.g., 50nm). Therefore, manufacturing the semiconductor sample for the TEManalysis requires a great deal of labor and time. Considering the rapidgrowth of the semiconductor industry, there is a need to quickly performa precise process for a TEM analysis sample.

In a conventional method of manufacturing the semiconductor sample forthe TEM analysis, stack, cutting, grinding, dimpling, and ion-millingprocesses are generally performed in this order. The grinding processincludes a front surface grinding process, a mirror surface polishingprocess, and a rear surface grinding process. That is, since the sampleis ground through the front surface grinding, mirror surface polishing,and rear surface grinding processes, two mounts (one is for the frontand rear surface grinding processes and the other is for the mirrorsurface polishing process) are necessary. In addition, since the samplemoves three times in the conventional grinding process, the number ofprocess steps increases. Therefore, according to the conventionalmethod, a great deal of labor and time is required to manufacture thesemiconductor sample for the TEM analysis.

SUMMARY

Embodiments presented here provide a grinding mount holder assembly thatcan reduce time and labor for performing a grinding process, and anapparatus and method for manufacturing a sample using the grindingprocess.

Embodiments provide grinding mount holder assemblies having a mountholder that can rotate by 180°.

In other embodiments, grinding mount holder assemblies may include: amount in which a sample is fitted; a holder in which the mount isinserted; and a base on which the holder is installed to be capable ofrotating, the base having a pressing or biasing member adapted to pressdown the mount inserted in the holder.

In some embodiments, the mount may have a space for exposing only onesurface of the sample. The holder may have a space in which the mount isinserted, the space of the holder having upper and lower opened ends.The base may include a fixing part for rotatably fixing the holder. Theholder may include a groove in which the fixing part is fitted.

In still other embodiments, grinding mount holder assemblies mayinclude: a cylindrical mount having a cylindrical end wall on which oneof front and rear surfaces of a sample is fixed, and a cylindricalvertical wall enclosing a side surface of the sample, the mount mountingthe sample so that the other of the front and rear surfaces of thesample is exposed; a cylindrical holder having a vertical wall defininga cylindrical opened space in which the mount is inserted and providedat an outer-middle portion with a groove; and a base having acylindrical vertical wall defining a cylindrical space in which theholder is rotatably installed and having a fixing part fitted in thegroove and a pressing member for pushing out the mount inserted in thecylindrical opened space of the holder.

In some embodiments, the holder may have an inner diameter equal to orgreater than a diameter of the mount and a height greater than that ofthe mount. The pressing member may be cylindrical to push the mount inthe cylindrical open space of the cylindrical holder. The holder mayrotate about an axis of the fixing part. The fixing part may be a screw.

In still yet other embodiments, grinding mount holder assemblies mayinclude: a mount in which a sample is fitted so that one of front andrear surfaces of the sample is exposed; a holder having an inner spacehaving upper and lower opened ends, the mount being inserted in theinner space of the holder; a base to which the holder is rotatablyscrew-coupled; wherein a pressing member for pressing down the mountinserted in the holder, the pressing member being provided in the base,wherein the grinding mount holder assembly allows one of the front andrear surfaces of the sample to be ground, rotates the holder 180°, andallows the other surface of the front and rear surfaces of the sample tobe ground without replacing the mount.

In some embodiments, the holder may be cylindrical so that the mount canbe inserted therein to be moveable. The holder may be cylindrical andhave a height greater than that of the mount. The base may include ascrew rotatably fixing the holder and the holder may be provided with agroove to which the screw is coupled.

In still yet another embodiments, sample manufacturing apparatuses mayinclude: a main body having a plurality of rotational disks; an arminstalled on the main body to be capable of moving leftward andrightward; and a grinding mount holder assembly installed on an extremeend of the arm to be capable of moving frontward and rearward, thegrinding mount holder assembly mounting a sample being ground by therotation of the rotational disks and reversing front and rear surfacesof the sample.

In some embodiments, the grinding mount holder assembly may include: amount in which a sample is fitted so that one of front and rear surfacesof the sample is exposed; a holder having an inner space having upperand lower opened ends, the mount being inserted in the inner space ofthe holder; a base to which the holder is rotatably screw-coupled; apressing member for pressing down the mount inserted in the holder, thepressing member being provided in the base, wherein the grinding mountholder assembly allows one of the front and rear surfaces of the sampleto be ground, rotates the holder 180°, and allows the other surface ofthe front and rear surfaces of the sample to be ground without replacingthe mount.

In other embodiments, the base may include a screw rotatably fixing theholder, and the holder may be provided with a groove to which the screwis coupled. The holder may be cylindrical so that the mount can beinserted therein to be moveable. The holder may be cylindrical and havea height greater than that of the mount. The mount may be formed ofbrass.

In still other embodiments, methods for manufacturing a sample mayinclude: disposing the sample fitted in a mount inserted in a holder sothat a front surface of the sample faces a lapping disk by pushing theholder using a pressing member; grinding the front surface of the sampleby rotating the lapping disk; mirror-polishing the front surface of thesample; rotating the holder by 180° on an axis that is perpendicular toan axis of rotation of the lapping disk after the pressing member isretracted; disposing the sample so that a rear surface of the samplefaces the lapping disk by pushing the pressing member; and grinding therear surface of the sample by rotating the lapping disk.

In some embodiments, one of the grinding of the front surface and thegrinding of the rear surface may use a plurality of lapping disksclassified by grinding thicknesses. The grinding of the rear surface mayinclude exposing the rear surface of the sample by grinding the mount.

In yet other embodiments, methods for manufacturing a sample using agrinding mount holder include providing a mount in which the sample isfitted so that a front surface of the sample is exposed, a holder inwhich the mount is inserted, a base to which the holder is rotatablyscrew-coupled, and a pressing member on the base to press down the mountinserted in the holder. The methods may include: grinding the frontsurface of the sample; mirror-polishing the front surface of the sample;rotating the holder having upper and lower opened ends; rotatablyscrew-coupling the holder to a base; rotating the holder by 180°; andgrinding a rear surface of the sample without replacing the mount.

According to some embodiments, since the mount holder can rotate by180°, the grinding and mirror surface polishing processes for the frontsurface of the sample and the grinding process for the rear surface ofthe sample can be accomplished using only one mount. Therefore, tomanufacture the sample for the TEM analysis, the grinding process isautomated, thereby reducing the expended time and effort, whileimproving the working efficiency.

BRIEF DESCRIPTION OF THE FIGURES

Non-limiting and non-exhaustive embodiments will be described withreference to the following figures, wherein like reference numeralsrefer to like parts throughout the various figures unless otherwisespecified. In the figures:

FIG. 1 is a perspective view of a sample manufacturing apparatusaccording to an embodiment;

FIG. 2 is a cross-sectional view of a grinding mount holder assemblyaccording to an embodiment;

FIGS. 3A and 3B are, respectively, cross-sectional and bottom views of apart of FIG. 2;

FIGS. 4A and 4B are, respectively, cross-sectional and bottom views ofanother part of FIG. 2;

FIGS. 5A and 5B are, respectively, cross-sectional and bottom views ofyet another part of FIG. 2; and

FIGS. 6 through 13 are cross-sectional views illustrating operationalsteps of the grinding mount holder assembly of FIG. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described belowin more detail with reference to the accompanying drawings. The presentinvention may, however, be embodied in different forms and should not beconstructed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the present inventionto those skilled in the art.

Like reference numerals in the drawings refer to like elements.

An exemplary embodiment will now be described in conjunction with theaccompanying drawings.

FIG. 1 is a perspective view of a sample manufacturing apparatusaccording to an embodiment.

Referring to FIG. 1, a sample manufacturing apparatus 100 is a polishingmachine for grinding a sample for use in a TEM analysis. The polishingmachine 100 may include a main body 102 and a grinding mount holderassembly 200 installed on a lower portion of an extreme end of an arm104 that can move in the body 102. The grinding mount holder assembly200 is configured to hold a sample. The arm 104 may be assembled withthe main body 102 to be capable of moving leftward and rightward. Thegrinding mount holder assembly 200 may be assembled with the arm 104 tobe capable of moving frontward and rearward.

The main body 102 has a plurality of lapping disks, or grinding wheels,106 a through 106 g configured to rotate at a predetermined RPM. Thereason for providing the plurality of the lapping disks 106 a through106 g is to be able to grind the sample by a multitude of grindingthicknesses. For example, the lapping disk 106 a is provided to grindthe sample by 40 μm, the lapping disk 106 b is provided to grind thesample by 15 μm, the lapping disk 106 c is provided to grind the sampleby 5 μm, and the lapping disk 106 d is provided to grind the sample by 1μm. The lapping disks 106 e through 106 g may be provided to perform amirror surface polishing process.

As the grinding mount holder assembly 200 contacts surfaces of thelapping disks 106 a through 106 g, the sample is ground. When the sampleis ground, slurry is supplied from the arm 104 to the lapping disks 106a through 106 g. When the grinder mount holder assembly 200 finishes agrinding job at one (e.g., the lapping disk 106 a) of the lapping disks106 a through 106 g and then moves to perform a grinding job at anotherlapping disk 106 b, deionized water may be sprayed to clean thejust-used lapping disk (e.g., 106 a).

Control boxes 108 a and 108 b may be provided in the main body 102. Thepolishing machine 100 may operate according to values or data assignedby the control boxes 108 a and 108 b. A monitor 109 may be provided tolet a worker identify a device state and a working condition.

FIG. 2 is a cross-sectional view of a grinding mount holder assemblyaccording to an embodiment. FIGS. 3A and 3B are, respectively,cross-sectional and bottom views of a part of FIG. 2. FIGS. 4A and 4Bare, respectively, cross-sectional and bottom views of another part ofFIG. 2. FIGS. 5A and 5B are, respectively, cross-sectional and bottomviews of another part of FIG. 2.

Referring to the embodiment of FIG. 2, the grinding mount holderassembly 200 includes a base 210 that may be assembled onto the arm 104.This assembly may then be capable of sliding frontward and rearward. Aholder 220 that is, in turn, assembled on the base 210 is capable ofrotating around an axis parallel to an exposed surface of the sample 300and perpendicular to an axis of rotation of the lapping disks 106 athrough 106 g by means disclosed further below. Furthermore, a mount 230that is inserted in the holder 220 may be capable of moving verticallyas by sliding within an open space defined between the vertical walls ofthe holder 220. A sample 300 is fixedly fitted in the mount 230. Apressing member 218 for forcing the mount 230 downward within the openspace of the holder 220 and against a lapping disk (e.g. lapping disk106 a) is provided on the base 210.

For example, the mount 230 may have a cylindrical shape so that thedisk-shaped sample 300 can be easily fitted therein. Likewise, theholder 220 may also have a cylindrical shape so that the cylindricalmount 230 can be easily inserted therein. Likewise, the base 210 mayalso have a cylindrical shape so that the cylindrical holder 220 can beeasily assembled therewith. It is understood, however, that the base 210must be shaped and sized to allow rotational movement of the holder 220therewithin so that either the top or bottom face of the mount 230 (andthus sample 300) may be exposed to one or more of the lapping disks.

As shown in FIGS. 3A and 3B, the base 210 may include a laterallyexpansive upper portion 212, a vertical wall 216 defining a space 217 inwhich the holder 220 may be installed, and a vertical wall 214 defininga space 215 in which the pressing member 218 may be installed. Thevertical walls 214 and 216 and the pressing member 218 may have acylindrical shape but, again, should be shaped and sized to allowrotational/pivotal movement of the holder 220 therewithin.

An inner diameter D₁ of the vertical wall 216, i.e., a diameter D₁ ofthe space 217, may be greater than an inner diameter D₂ of the verticalwall 214, i.e., a diameter D₂ of the space 215. The vertical wall 216may be provided with a fixing part such as screws 219 that can fix theholder 220 in the space 217. The screws 219 may penetrate the verticalwall 216 from outside the vertical wall 216 to inside.

As shown in FIGS. 4A and 4B, the holder 220 may include a vertical wall222 having a height HI. The vertical wall 222 defines a space 224 havingupper and lower opened ends. Grooves 226 in which the screws 219 arefitted may be formed on an outer circumferential middle portion. As thescrews 219 are fitted in the grooves 226, the holder 220 can be fixed inthe space 217 of the vertical wall 216 of the base 210. The holder 220may be configured to rotate about an axis defined by both screws 219.Since the holder 220 must be capable of rotating in the space 217 of thebase 210, an outer diameter D₃ and the height H₁ of the vertical wall222 of the holder 220 is preferably less than the dimensional diameterD₁ of the space 217 of the base 210. The holder 220 may be a thin diskwith the height H₁ less than its diameter D₃ The inner space 224 of theholder 220 preferably has a sufficient diameter D₄ for receiving themount 230.

The pressing member 218 is configured to extend downward into space 224of the holder 220 and press down or downwardly bias the mount 230inserted in the space 224. Therefore, the pressing member 218 must becapable of vertically sliding. A diameter D₈ of the pressing member 218is slightly less than a diameter D₄ of the space 224, i.e., an innerdiameter D₄ of the holder 220.

When the rotation of the holder 220 is realized by a driving source suchas a motor, it is convenient to automate the grinding work.

As shown in FIGS. 5A and 5B, the mount 230 has an end wall 232 and avertical wall 234 to define a space 235 having an open side. The sample300 may be fitted in the space 235 in a state where a front surface 302of the sample 300 is exposed and a rear surface 304 of the sample 300contacts an inner surface 232 a of the end wall 232. Since the space 235can receive the sample 300, a diameter D₆ of the space 235, i.e., aninner diameter D₆ of the vertical wall 234, is equal to or slightlygreater than a diameter D₇ of the sample 300. In addition, since thefront surface 302 of the sample 300 contacts the lapping disks 106 athrough 106 g during the grinding process, a height H₃ of the space 235is preferably equal to or slightly less than a thickness T of the sample300.

Since the mount 230 is inserted in the holder 220, a diameter D₅ of themount 230, i.e., an outer diameter D₅ of the vertical wall 234, ispreferably slightly less than the diameter D₄ of the inner space 224 ofthe holder 220. Then, since the mount 230 is inserted in the inner space224 of the holder 220 to be capable of vertically sliding, the height H₂of the mount 230 is preferably less than the height HI of the holder220.

The mount 230 may be considered an expendable element. That is, themount 230 may be formed of a material that can be easily worn when thesample 300 is ground. For example, when the sample 300 is formed of asilicon material, the mount 230 may be formed of silicon or brass.

When the sample 300, for example, has a diameter D₇ of 3 mm and athickness T of 1 mm, the diameter D₆ and height H₃ of the space 235 inwhich the sample 300 may be fitted may be respectively 3.2 mm and 1 mm.When the diameter D₅ and height H₂ of the mount 230 are respectively 1cm and 2 mm, the diameter D₃ and height H₁ of the space 224 in which themount 230 will be fitted may be 5 cm and 3 cm.

FIGS. 6 through 13 are cross-sectional views illustrating operationalsteps of the grinding mount holder assembly of FIG. 2, according to someembodiments.

As shown in FIG. 6, a mount wax (not shown) may be deposited on theinner surface 232 a of the end wall 232 of the mount 230, before whichthe mount 230 may be pre-heated up to, for example, 100-150° C. so thatthe mount wax can be easily melted. Then, the sample 300 may be fittedinto the space 235 so that the rear surface 304 of the sample 300 facesthe inner surface 232 a on which the mount wax is deposited. Then, thesample 300 may be fixed in the mount 230 with the front surface 302exposed.

As shown in FIG. 7, when the sample 300 is fitted in the mount 230 withthe front surface 302 exposed, the mount 230 is inserted into the innerspace 224 of the holder 220 so that the vertical wall 234 of the mount230 may contact the vertical wall 222 of the holder 220. Then the frontsurface 302 of the sample 300 is exposed to an external side of theholder 220.

As shown in FIG. 8, when the mount 230 is inserted in the holder 220,the holder 220 is mounted in the space 217 formed by the vertical wall216 of the base 210. The vertical wall 222 of the holder 220 faces thevertical wall 216 of the base 210 so that the screws 219 can be fittedin the grooves 226. When the screws 219 are fitted in the grooves 226,the holder 220 is pivotally mounted on the base 210 and is capable ofrotating about an axis defined by the screws 219 and grooves 226. In afirst presented position, the front surface 302 of the sample 300 mayface the lapping disk 106 a.

As shown in FIG. 9, when the holder 220 is installed in the base 210,the base 210 may be lowered so that the front surface 302 of the sample300 comes near or contacts the lapping disk 106 a. The pressing member218 can move downward to press down the mount 230. The front surface 302of the sample 300 can then be ground by the rotation of the lapping disk106 a. The slurry and/or deionized water may be supplied to the lappingdisk 106 a. When the grinding process using the lapping disk 106 a isfinished, the base 210 may be moved above the lapping disks 106 b-106 dto perform a subsequent grinding process.

For example, as shown for the embodiment of FIG. 10, when the grindingprocess for the front surface 302 of the sample 300 is finished, thebase 210 is moved above the lapping disk 106 e to perform the mirrorsurface polishing process.

As shown in FIG. 11, when the grinding and polishing processes for thefront surface 302 of the sample 300 are finished, the pressing member218 pressing down the mount 230 may move upward out of holder opening224 to thereby separate from the holder 220. Then the holder 220 mayrotate 180° to a second presented position so that the front surface 302of the sample 300 faces the pressing member 218. The rotation of theholder 220 may be realized by a driving source such as a motor.

As shown in FIG. 12, the pressing member 218 may move to push the mount230 downward of the holder 220 so that the rear surface 304 of thesample 300 faces the lapping disk 106 a of the end wall 232 of the mount230. Then, the base 210 is moved downward so that the end wall 232 ofthe mount 230 contacts the rotating lapping disk 106 a. At this point,the pressing member 218 may keep pressing down the mount 230. Therefore,the end wall 232 is ground to finally expose the rear surface 304 of thesample 300. Then, the exposed rear surface 304 is in turn ground, in thecourse of which the slurry and/or deionized water is supplied to thelapping disk 106 a.

As shown in FIG. 13, when the above-described steps are performed, thegrinding and mirror surface polishing processes for the front surface302 of the sample 300 and the grinding process for the rear surface 304of the sample 300 can be realized without replacing the mount 230. As aresult, a sample 300′ can be easily manufactured.

According to the embodiments described above, since the mount holder canrotate by 180°, the grinding and mirror surface polishing processes forthe front surface of the sample and the grinding process for the rearsurface of the sample can be realized using only one mount. Therefore,to manufacture the sample for a TEM analysis, the grinding process isautomated, thereby reducing time and effort, while improving workingefficiency.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true spirit and scope of the present invention. Thus, to the maximumextent allowed by law, the scope of the present invention is to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing detailed description.

1. A grinding mount holder assembly comprising: a mount in which asample is fitted; a holder in which the mount is inserted; and a base inwhich the holder is rotatably disposed, the base having a pressingmember adapted to press down the mount inserted in the holder, whereinthe holder is configured to rotate relative to the base.
 2. The grindingmount holder assembly of claim 1, wherein the mount includes a firstspace to hold the sample, the first space configured to expose only onesurface of the sample.
 3. The grinding mount holder assembly of claim 1,wherein the holder includes a second space in which the mount isinserted, and wherein the holder further includes upper and lower openedends, between which the second space is disposed.
 4. The grinding mountholder assembly of claim 1, wherein the base includes a fixing part forrotatably fixing the holder in a rotation position relative to the base.5. The grinding mount holder assembly of claim 4, wherein the holderincludes a groove in which the fixing part is fitted, the fixing partextending through a sidewall of the base and into the groove.
 6. Agrinding mount holder assembly comprising: a mount including an end walladapted to fixedly receive one of front and rear surfaces of a sample,and having a side wall enclosing a side surface of the sample, the mountadapted to mount the sample so that the other of the front and rearsurfaces of the sample is exposed; a holder including a vertical walldefining an open space in which the mount is inserted at an end portionof the holder; and a base including a vertical wall defining a space inwhich the holder is rotatably installed, and further including apressing member for pushing out the mount inserted in the open space ofthe holder.
 7. The grinding mount holder assembly of claim 6, whereinthe holder has an inner diameter equal to or greater than a diameter ofthe mount and a height greater than that of the mount.
 8. The grindingmount holder assembly of claim 6, wherein the pressing member, themount, the open space, and the holder are each cylindrical.
 9. Thegrinding mount holder assembly of claim 6, wherein the holder includes agroove to receive a fixing part from the vertical wall of the base, andthe holder is adapted to rotate about an axis of the fixing part. 10.The grinding mount holder assembly of claim 6, wherein the fixing partis a screw.
 11. A sample manufacturing apparatus comprising: a main bodyhaving a plurality of rotational disks; an arm installed on the mainbody to be capable of moving leftward and rightward; and a grindingmount holder assembly installed on the arm to be capable of movingfrontward and rearward, the grinding mount holder assembly capable ofmounting a sample so that one of a front and rear surface of the sampleis ground by the rotational disks, and further capable of reversing thefront and rear surfaces of the sample so that the other one of the frontand rear surface of the sample is ground by the rotational disks. 12.The sample manufacturing apparatus of claim 11, wherein the grindingmount holder assembly comprises: a mount in which a sample is fitted sothat one of front and rear surfaces of the sample is exposed; a holderhaving an inner space having upper and lower opened ends, the mountdisposed in the inner space of the holder; a base to which the holder isrotatably coupled; and a pressing member for pressing down the mountdisposed in the holder, the pressing member being provided in the base,wherein the grinding mount holder assembly allows one of the front andrear surfaces of the sample to be ground, is capable of rotating theholder 180°, and allows the other surface of the front and rear surfacesof the sample to be ground without the mount being replaced.
 13. Thesample manufacturing apparatus of claim 12, wherein the base includes ascrew rotatably fixing the holder, and the holder is provided with agroove to which the screw is coupled.
 14. The sample manufacturingapparatus of claim 12, wherein the holder is cylindrical so that themount is inserted therein to be capable of moving.
 15. The samplemanufacturing apparatus of claim 12, wherein the holder is cylindricaland has a height greater than that of the mount.
 16. The samplemanufacturing apparatus of claim 12, wherein the mount is formed ofbrass or silicon.
 17. A method for manufacturing a sample, comprising:placing the sample in a mount that is inserted in a holder so that afront surface of the sample faces a lapping disk; pushing the mount by apressing member so that the sample is contacting the lapping diskpressing member; grinding the front surface of the sample by rotatingthe lapping disk; mirror-polishing the front surface of the sample;rotating the holder including the mount by 180° after the pressingmember is retracted; disposing the sample so that a rear surface of thesample faces the lapping disk; pushing the 180°-rotated mount by thepressing member so that the sample is contacting the lapping disk; andgrinding the rear surface of the sample by rotating the lapping disk.18. The method of claim 17, wherein one of the grinding of the frontsurface and the grinding of the rear surface uses a plurality of lappingdisks classified by grinding thicknesses.
 19. The method of claim 17,wherein the grinding of the rear surface includes exposing the rearsurface of the sample by grinding the mount.
 20. A method formanufacturing a sample using a grinding mount holder comprising a mountin which the sample is fitted so that a front surface of the sample isexposed, a holder in which the mount is inserted, a base to which theholder is rotatably coupled, and a pressing member provided on the baseto press down the mount inserted in the holder, the method comprising:grinding the front surface of the sample; mirror-polishing the frontsurface of the sample; rotating the mount in the holder; and; grinding arear surface of the sample without replacing the mount.
 21. The methodof claim 20, wherein the holder includes upper and lower opened ends.22. The method of claim 20, further comprising rotating the holder by180° before grinding the rear surface of the sample.
 23. A grindingmount holder assembly for positioning a sample, the assembly comprising:a base configured to position the sample over a plurality of grindingwheels; a sample holder pivotally connected along an axis to the base;and a pressing member disposed in the base adapted to press a side ofthe sample against one of the plurality of grinding wheels.
 24. Thegrinding mount holder assembly of claim 21, wherein the sample holder isconfigured to rotate so that the pressing member can press another sideof the sample against one of the plurality of grinding wheels.
 25. Thegrinding mount holder assembly of claim 21, further comprising a samplemount to hold the sample, the sample mount slideably disposed in thesample holder,